examples

commit 14d3d89dd20b1ce52b9eb7b84584243e63f5e9a8
parent 8a7c022626e1301f9d7420d964075fceadd0a638
Author: Henry Wilson <henry@henryandlizzy.uk>
Date:   Thu, 21 Apr 2022 23:53:24 +0100

gl-asteroids: Add sound to asteroids

Diffstat:
M
makefile
 | 
2
+-
M
src/gl-asteroids.cpp
 | 
35
+++++++++++++++++++++++++++++++++++

2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/makefile b/makefile
@@ -18,7 +18,7 @@ clean:
 	$(RM) $(c_targets) $(cpp_targets)
 
 aio: -lrt
-gl-asteroids: -lglfw -lGL -lm
+gl-asteroids: -lglfw -lGL -lm -lasound
 io_uring: -luring
 pulse-async-client: -lpulse
 pulse-simple-client: -lpulse-simple -lm
diff --git a/src/gl-asteroids.cpp b/src/gl-asteroids.cpp
@@ -1,4 +1,5 @@
 #include <GLFW/glfw3.h>
+#include <alsa/asoundlib.h>
 #include <cmath>
 #include <vector>
 #include <span>
@@ -10,6 +11,34 @@
 #include <chrono>
 #include <optional>
 #include <functional>
+#include <atomic>
+
+std::atomic_flag beep;
+
+void sound_routine(std::stop_token token)
+{
+	snd_pcm_t* handle;
+
+	snd_pcm_open(&handle, "default", SND_PCM_STREAM_PLAYBACK, 0);
+	snd_pcm_set_params(handle, SND_PCM_FORMAT_S16, SND_PCM_ACCESS_RW_INTERLEAVED, 1, 48000, 1, 10000);
+
+	while (not token.stop_requested())
+	{
+		std::array<short, 2048> buf;
+		if (beep.test())
+		{
+			beep.clear();
+			for (unsigned i = 0; i < buf.size(); ++i)
+				buf[i] = (i % 256 - 128) * 50;
+		}
+		else
+			for (auto& s : buf)
+				s = 0;
+		snd_pcm_sframes_t frames = snd_pcm_writei(handle, buf.data(), buf.size());
+	}
+	snd_pcm_drain(handle);
+	snd_pcm_close(handle);
+}
 
 struct coord
 {
@@ -328,6 +357,8 @@ int main(int argc, char* argv[])
 	for (auto& c : starsv)
 		c.x = dis_p(gen), c.y = dis_p(gen);
 
+	std::jthread sound(sound_routine);
+
 	while (!glfwWindowShouldClose(w) && not is_pressed(GLFW_KEY_ESCAPE))
 	{
 		float t = glfwGetTime();
@@ -401,6 +432,7 @@ int main(int argc, char* argv[])
 
 		if (is_pressed(GLFW_KEY_SPACE) && bullet_time < t && ammo)
 		{
+			beep.test_and_set();
 			--ammo;
 			bullet_time = t + 1/firerate;
 
@@ -454,6 +486,7 @@ int main(int argc, char* argv[])
 			{
 				if (is_colliding(r->p, b->p))
 				{
+					beep.test_and_set();
 					for (unsigned j = 0; j < 7; ++j)
 					{
 						entity debris = *r;
@@ -506,6 +539,8 @@ int main(int argc, char* argv[])
 				if (not is_colliding(b->p, powerups->p))
 					continue;
 
+				beep.test_and_set();
+
 				for (unsigned j = 0; j < 4; ++j)
 				{
 					entity debris = *powerups;